Dr. James Andrews
"One issue is that high school pitchers are throwing too hard, and their ligaments aren't maturing quickly enough to keep up with their velocity. Year-round baseball is another issue, as is throwing breaking balls at a young age. High school pitchers who throw harder than 80-85 MPH also run the risk of having arm issues."http://www.mlbtraderumors.com/2014/0...medium=twitter